A car travels 30 miles in 2 hours. What is its average speed?
The average speed is 15 mph.
How to work it out
- 1
Write down what you know: distance d = 30 miles, time t = 2 hours. You are asked for the speed v.
- 2
Use the formula speed = distance ÷ time:
- 3
Answer with the unit: 15 mph.
- 4
The same formula rearranged: distance = speed × time (15 × 2 = 30 miles) and time = distance ÷ speed (30 ÷ 15 = 2 hours).
LaTeX source of the formulas on this page
\[ v = \frac{d}{t} = \frac{30}{2} = 15\ \text{mph} \]
\[ v = \frac{d}{t} = \frac{30}{2} = 15 \]How far at 15 mph
| Time | Distance |
|---|---|
| 0.5 hours | 7.5 miles |
| 1 hour | 15 miles |
| 2 hours | 30 miles |
| 3 hours | 45 miles |
| 4 hours | 60 miles |
| 5 hours | 75 miles |
Questions
What is the speed if a car travels 30 miles in 2 hours?
The average speed is 15 mph.
How far does it go in 3 hours at that speed?
45 miles.